Diagnostic imaging is important in ophthalmology. Optical coherence tomography (OCT) is utilized more and more in recent years. OCT is used not only for the acquisition of B mode images and three dimensional images but also for the acquisition of front images (or enface images) such as C mode images and shadowgrams.
In addition, there are diagnostic imaging technique for acquiring images in which a specific site of an eye is enhanced, and for acquiring functional information. For example, based on time-series volume data acquired with OCT, B mode images and front images in which retinal blood vessels and choroid blood vessels are enhanced can be constructed. Such images are referred to as blood vessel enhanced images, blood vessel high-contrast images, angiograms, or the like. Such imaging technique is referred to as OCT angiography or the like. Further, blood flow information can be determined based on phase information of data acquired with OCT. Such imaging technique is referred to as OCT blood flow measurement, or the like.
Conventional technology related to the above is disclosed, for example, in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2015-515894, and Japanese Unexamined Patent Application Publication No. 2013-184018.